1. INFSO-SSA-26637 International Collaboration to Extend and Advance Grid Education Information System Valeria Ardizzone INFN Catania Corso di Grid Computing Catania, 22.05.2007

2. INFSO-SSA-26637 2 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Information System What is? – System to collect information on the state of resources Why? – To discover resources of the grid and their nature – To have useful data that helps who is in charge of managing the workload to do it more efficiently. – To check for health status of resources. How? – Monitoring state of resources locally and publishing right information on the information system. – Adopting a data model that MUST be well known to all components that want to access monitored information – Using different approaches that we are going to investigate in next slides

3. INFSO-SSA-26637 3 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Adopted Information Systems The BDII (Berkley DB Information Index) – has been adopted in LCG middleware as the Information System provider. – It is an evolution of the Globus Meta Directory System (MDS) – LCG-2 actually adopts BDII as Information System. – It is based on Lightweight Directory Access Protocol (LDAP) servers. The Relational Grid Monitoring Architecture (R-GMA) – Is an implementation of the Grid Monitoring Architecture (GMA) standardized by the Global Grid Forum (GGF) – It is a relational implementation of the GMA – It is strongly Web Services Oriented – It will be adopted by gLite middleware

4. INFSO-SSA-26637 4 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 LCG Information System

5. INFSO-SSA-26637 5 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Collecting Information Gathering of information at different levels – Lower level: Grid Resource Information Server (GRIS)  Collects information on the state of a given resource  One GRIS on top of each resource  A set of scripts and sensor that try to extract useful info on the resource – Medium level: Grid Index Information Server (GIIS)  Collects information on resources of a given site  One GIIS for each site – Higher level: BDII  Collects information on resources of a given VO  One BDII for each VO (suggested solution) Way of collecting info – Pull model (higher level servers periodically query lower level servers) – LDAP query model

6. INFSO-SSA-26637 6 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 BDII (the present) The Berkley Database Information Index (BDII) – Developed within the context of LCG project – Solves problems of instability of the MDS occurring when the number of sites grows too much – Stays on top of GIIS sites – One for each VO – Centralized system – Three levels of hierarchy – Accessed by the Workload Management System Way of working – One GRIS for each resource – One GIIS for each site collecting info from below GRIS systems – One BDII for a given VO collecting information from below GIIS systems – Two LDAP servers, one for write access and one for read access – Every two minutes a cron-job runs a script and collects info from a list of GIIS sites – The list of GIIS is placed in the configuration file of the BDII

7. INFSO-SSA-26637 7 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals Ensure that the LCG_GFAL_INFOSYS enviroenment is set: – export LCG_GFAL_INFOSYS=grid004.ct.infn.it:2170 The commands to query the Top BDII are: – lcg-info – lcg-infosites

8. INFSO-SSA-26637 8 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 lcg-info

9. INFSO-SSA-26637 9 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfo (1/5) -h/--help: to see the help –list-attrs: print the list of the possible attributes --list-ce: lists the CEs which satisfy a query, or all the CEs if no query is given. --list-se: lists the SEs which satisfy a query, or all the SEs if no query is given. --bdii: allows to specify a BDII in the form :. If not given, the value of the environmental variable LCG_GFAL_INFOSYS is used. If that is not defined, the command returns an error. --vo: restricts the output to CEs or SEs where the given VO is authorized.

10. INFSO-SSA-26637 10 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfo (2/5) Examples: $ lcg-info --vo gilda --list-ce - CE: ce-gilda-edu.ceta-ciemat.es:2119/jobmanager-lcgpbs- infinite - CE: ce-gilda-edu.ceta-ciemat.es:2119/jobmanager-lcgpbs- long - CE: ce-gilda-edu.ceta-ciemat.es:2119/jobmanager-lcgpbs- short - CE: ce-nano-37.to.infn.it:2119/jobmanager-lcgpbs-infinite -CE: ce-nano-37.to.infn.it:2119/jobmanager-lcgpbs-long …..

11. INFSO-SSA-26637 11 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfo (3/5) $ lcg-info --vo gilda --list-se - SE: aliserv6.ct.infn.it - SE: dgt02.ui.savba.sk - SE: egee016.cnaf.infn.it - SE: gilda-se-01.pd.infn.it - SE: gilda04.ihep.ac.cn - SE: gn0.hpcc.sztaki.hu …..

12. INFSO-SSA-26637 12 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfo (4/5) $ lcg-info --vo gilda --list-attrs ….. $ lcg-info --vo gilda --attrs TotalCPUs --list-ce - CE: ce-gilda-edu.ceta-ciemat.es:2119/jobmanager-lcgpbs-infinite - TotalCPUs 1 - CE: ce-gilda-edu.ceta-ciemat.es:2119/jobmanager-lcgpbs-long - TotalCPUs 1 - CE: ce-gilda-edu.ceta-ciemat.es:2119/jobmanager-lcgpbs-short - TotalCPUs 1 - CE: ce-nano-37.to.infn.it:2119/jobmanager-lcgpbs-infinite - TotalCPUs 4 - CE: ce-nano-37.to.infn.it:2119/jobmanager-lcgpbs-long - TotalCPUs 4

13. INFSO-SSA-26637 13 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfo (5/5) $ lcg-info --vo gilda --attrs AvailableSpace,UsedSpace --list-se - SE: aliserv6.ct.infn.it - AvailableSpace 2450000000 - UsedSpace 1400000000 - SE: dgt02.ui.savba.sk - AvailableSpace 28295068 - UsedSpace 2039496 - SE: egee016.cnaf.infn.it - AvailableSpace 63530000 - UsedSpace 10540000

14. INFSO-SSA-26637 14 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 lcg-infosites

15. INFSO-SSA-26637 15 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfosites (1/6) -h/--help: help option --vo: VO name (mandatory) --is: it's possible to specify a not default Top BDII Some options: – se: The names of the SEs supported by the user's VO – ce: The information relative to number of CPUs, running jobs,etc. – rb: Names of the Rbs available for each VO – sitenames: Names of the LCG sites – tag: The names of the tags relative to the software installed in site is printed together with the corresponding CE – closeSE: The names of the CEs where the user's VO is allowed to run together with their corresponding closest SEs are provided

16. INFSO-SSA-26637 16 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfosites (2/6) Examples: $ lcg-infosites --vo gilda ce #CPU Free Total Jobs Running Waiting ComputingElement ---------------------------------------------------------- 1 1 0 0 0 ce-gilda-edu.ceta- ciemat.es:2119/jobmanager-lcgpbs-short 1 1 0 0 0 ce-gilda-edu.ceta- ciemat.es:2119/jobmanager-lcgpbs-long 1 1 0 0 0 ce-gilda-edu.ceta- ciemat.es:2119/jobmanager-lcgpbs-infinite 22 22 0 0 0 grid010.ct.infn.it:2119/jobmanager- lcgpbs-short 22 22 0 0 0 grid010.ct.infn.it:2119/jobmanager- lcgpbs-long 22 22 0 0 0 grid010.ct.infn.it:2119/jobmanager- lcgpbs-infinite

17. INFSO-SSA-26637 17 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfosites (3/6) $ lcg-infosites --vo gilda se Avail Space(Kb) Used Space(Kb) Type SEs ---------------------------------------------------------- 2890000 3020000 n.a se01-gilda-edu.ceta-ciemat.es 251640000 16960000 n.a grid0028.datagrid.cnr.it 251770000 16830000 n.a grid0029.datagrid.cnr.it 2450000000 1400000000 n.a aliserv6.ct.infn.it 8827616 740836 n.a trigriden01.unime.it

18. INFSO-SSA-26637 18 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfosites (3/6) $ lcg-infosites --vo gilda sitenames CE-CETA-CIEMAT CNR-ROMA GILDA-INFN-CATANIA GILDA-ING-MESSINA GILDA-TORINO ICEAGE-CATANIA IHEP-BEIJING ….

19. INFSO-SSA-26637 19 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfosites (4/6) $ lcg-infosites --vo gilda tag Name of the CE: grid010.ct.infn.it VO-gilda-scons-0.96.1 VO-gilda-GILDA-echo VO-gilda-GILDA-gilda VO-gilda-GRELC_DAS_2_1 …..

20. INFSO-SSA-26637 20 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfosites (5/6) $ lcg-infosites --vo gilda rb glite-rb.ct.infn.it:7772 $ lcg-infosites --vo gilda lfc lfc-gilda.ct.infn.it gilda02.ihep.ac.cn

21. INFSO-SSA-26637 21 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Praticals: lcginfosites (6/6) $ lcg-infosites --vo gilda closeSE Name of the CE: ce-gilda-edu.ceta- ciemat.es:2119/jobmanager-lcgpbs-short se01-gilda-edu.ceta-ciemat.es Name of the CE: grid0021.datagrid.cnr.it:2119/jobmanager-lcgpbs- infinite grid0028.datagrid.cnr.it Name of the CE: grid010.ct.infn.it:2119/jobmanager- lcgpbs-short aliserv6.ct.infn.it …..

22. INFSO-SSA-26637 22 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 References LCG-2 User Guide – https://edms.cern.ch/file/454439//LCG-2- UserGuide.html https://edms.cern.ch/file/454439//LCG-2- UserGuide.html GLUE Schema – http://infnforge.cnaf.infn.it/glueinfomodel/ http://infnforge.cnaf.infn.it/glueinfomodel/

23. INFSO-SSA-26637 23 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 RELATIONAL GRID MONITORING ARCHITECTURE (RGMA)

24. INFSO-SSA-26637 24 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Grid Monitoring Architecture(GMA) PRODUCER CONSUMER REGISTRY Store location Lookup location Transfer Data The Producer stores its location (URL) in the Registry. The Consumer looks up producer URLs in the Registry. The Consumer contacts the Producer to get all the data or the Consumer can listen to the Producer for new data.

25. INFSO-SSA-26637 25 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 R-GMA: Schema-Registry- Mediator VIRTUAL DATABASE TABLE 1, Colum defs TABLE 2, Colum defs TABLE 3, Colum defs TABLE 4, Colum defs SCHEMA TABLE 1,Producer P1 details TABLE 2,Producer P1 details TABLE 2,Producer P2 details TABLE 2,Producer P3 details TABLE 3,Producer P2 details TABLE 3,Producer P1 details TABLE 3,Producer P3 details REGISTRY MEDIATOR R-GMA Server MEDIATOR: a set of rules for deciding which data providers to contact for any given query. REGISTRY: It holds the details of all producers that are publishing to tables in the virtual database and it also holds the details of “continuous” consumers. SCHEMA : it holds the names and definitions of all of the tables in the virtual database, and their authorization rules.

26. INFSO-SSA-26637 26 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 R-GMA: Producer-Consumer VIRTUAL DATABASE TABLE 1, Colum defs TABLE 2, Colum defs TABLE 3, Colum defs TABLE 4, Colum defs SCHEMA TABLE 1,Producer P1 details TABLE 2,Producer P1 details TABLE 2,Producer P2 details TABLE 2,Producer P3 details TABLE 3,Producer P2 details TABLE 3,Producer P1 details TABLE 3,Producer P3 details REGISTRY MEDIATOR P1 P2 P3 C1C2 SQL “INSERT” SQL “SELECT” Producers: are the data providers for the virtual database. Writing data into the virtual database is known as publishing, and data is always published in complete rows, known as tuples. There are three types of producer: Primary, Secondary and On-demand. Consumer: represents a single SQL SELECT query on the virtual database. The query is matched against the list of available producers in the Registry. The consumer service then selects the best set of producers to contact and sends the query directly to each of them, to obtain the answer tuples. R-GMA Server

27. INFSO-SSA-26637 27 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 R-GMA command line tool

28. INFSO-SSA-26637 28 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Before you start the R-GMA command line tool make sure you have a proxy certificate : Run the command and you should receive the following message on startup: R-GMA Command Line Tool > voms-proxy-info --all $ rgma Welcome to the R-GMA virtual database for Virtual Organisations. ================================ Your local R-GMA server is: https://rgma.eumedgrid.eun.eg:8443/R-GMA …… rgma>

29. INFSO-SSA-26637 29 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Commands are entered by typing at the > rgma prompt and hitting ‘enter’ to execute the command. A history of the commands executed can be accessed using the Up and Down arrow keys. To search a command from history use CTRL-R and type the first few letters of the command to recall. Command autocompletion is supported (use Tab when you have partly entered a command). Commands

30. INFSO-SSA-26637 30 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 General Commands help and help Display general help information or specific for a command. exit or q Exit from R-GMA command line interface. Show and set …Banal! clear history Clear the current session history of commands executed. write history Write the session command history to a file. write results Write query results to a file. read Read in the specified file and execute the commands contained in it.

31. INFSO-SSA-26637 31 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Table Commands Show tables Display the name of all tables existing in the Schema Describe Show all information about the structure of a table create table Create a table in the R-GMA schema. drop table Delete a table in the R-GMA schema.

32. INFSO-SSA-26637 32 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Exercise 1: create a table (1/2) rgma> create TABLE TutorTable(COD_Test INT PRIMARY KEY, Application VARCHAR(20), Status VARCHAR(10), PercStatus INT, Owner VARCHAR(25)) rgma> show tables ……. | NetworkUDPPacketLoss | | NetworkFileTransferThroughput | | TutorTable |

33. INFSO-SSA-26637 33 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 rgma> describe TutorTable +-----------------+------------+-------------------------+- ---------------+------------------+ | Column name | Type | Primary key | Can be NULL | +-----------------+-------------+------------------------+ ----------------+------------------+ | COD_Test | INTEGER | Yes | No | | Application | VARCHAR(20) | No | Yes | | Status | VARCHAR(10) | No | Yes | | PercStatus | INTEGER | No | Yes | | Owner | VARCHAR(25) | No | Yes | | MeasurementDate | DATE | No | No | | MeasurementTime | TIME | No | No | +-----------------+------------+-------------------------+ ----------------+------------------+ Exercise 1: create a table (2/2)

34. INFSO-SSA-26637 34 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Producer Types Primary Producer Secondary Producer On-Demand Producer User Code Producer API Producer Service Tuple Storage C Control only Queries Tuples SELECT * Tuples P User Code Producer API Producer Service C Control only Queries Tuples Queries User Code Producer API Producer Service Tuple Storage C Control and inserted tuples Queries Tuples

35. INFSO-SSA-26637 35 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Query and Storage Types Continuous: as soon as new data becomes available it is broadcast to all interested parties. Latest: correspond to intuitive idea of “current information”. History: return time sequenced data. TABLE 1,Producer P1 details TABLE 2,Producer P1 details TABLE 2,Producer P2 details TABLE 2,Producer P3 details TABLE 3,Producer P2 details TABLE 3,Producer P1 details TABLE 3,Producer P3 details REGISTRY P1 Latest-store Continuous&History-store P1 LATEST RETENTION PERIOD (LRP) and HISTORY RETENTION PERIOD (RTP) allow producers to periodically purge old tuples, and to give a precise meaning to the “current state”. Tuple-store can be in Memory or Database

36. INFSO-SSA-26637 36 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Continuous Producer Servlet Registry Store location Lookup location Continuous Store table description Producer API SQL “CREATE TABLE” Result Set TableName Value 1Value 2 TableNameURLPredicate Schema TableNameColumn TableName Value 1Value 2 Insert TableName UKRALAlice Consumer ServletConsumer API SQL “SELECT” TableName Value 1Value 2 TableName Value 1Value 2 Query SQL “INSERT”

37. INFSO-SSA-26637 37 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 History or Latest Producer Servlet Registry Store location Lookup location Query Store table description Producer API SQL “CREATE TABLE” Result Set TableName Value 1Value 2 TableNameURLPredicate Schema TableNameColumn TableName Value 1Value 2 Insert TableName UKRALAlice Consumer ServletConsumer API SQL “SELECT” TableName Value 1Value 2 TableName Value 1Value 2 Query SQL “INSERT”

38. INFSO-SSA-26637 38 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Producer Properties (cli) Using the command line tool you may work with one producer at a time. The current producer type can be displayed using: rgma>show producer Set the latest retention period for tuples published by the producer rgma>set producer latestretentionperiod | lrp [ ] Set the history retention period for the producer. If the producer does not support history queries this command has no effect. rgma>set producer historyretentionperiod | hrp [ ] Producer which handles the INSERT statement. The SQL INSERT statement may be used to add data to the system: rgma> INSERT INTO VALUES (’a’, ’b’, ’c’, ’d’)

39. INFSO-SSA-26637 39 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Exercise 2: create a Producer rgma> set producer latest Producer type : continuous latest rgma> set producer latestretentionperiod 50 seconds Set producer LRP to 50 seconds rgma> set producer historyretentionperiod 2 minutes Set producer HRP to 2 minutes rgma>describe TutorTable rgma> insert INTO TutorTable values(001,'TestProducer','Start',10,'Valeria'); Inserted 1 row into ITATutTable

40. INFSO-SSA-26637 40 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Consumer Properties (cli) 1 The behaviour of Consumer varies according to the type of query being executed. In R-GMA there are three basic types of query: LATEST Queries: only the most recent tuple for each primary key HISTORY Queries: all historical tuples for each primary key CONTINUOUS Queries: returns tuples continuously as they are inserted. The type of query can be changed using the SET QUERY command as follow: rgma> SET QUERY LATEST | CONTINUOUS | HISTORY The current query type can be displayed using rgma> SHOW QUERY

41. INFSO-SSA-26637 41 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Consumer Properties (cli) 2 The maximum age of tuples to return can also be controlled. To limit the age of latest or historical tuples use the MAXAGE property. rgma> SET MAXAGE seconds | minutes | hours | days The current maximum tuple age can be displayed using rgma> SHOW MAXAGE To disable the maximum age, set it to none: rgma> SET MAXAGE none

42. INFSO-SSA-26637 42 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 The final property affecting queries is timeout. – For a latest or history query the timeout exists to prevent a problem (e.g. network failure) from stopping the query from completing. – For a continuous query, timeout indicates how long the query will continue to return new tuples. Default timeout is 1 minute and it can be changed using rgma>SET TIMEOUT seconds | minutes | hours | days The current timeout can be displayed using rgma>SHOW TIMEOUT Consumer Properties (cli) 3

43. INFSO-SSA-26637 43 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Querying data uses the standard SQL SELECT statement: rgma> SELECT * FROM Set the output format for results. 'table' formats the results in a table, tsv outputs tab-separated results and csv outputs comma-separated results: rgma> SET output table|tsv|csv Consumer Properties (cli) 4 output csv: 1,TestProducer,Start,10,Valeria,2006-12-07,22:07:36, set output tsv: 1 TestProducer Start 10 Valeria 2006-12-07 22:07:36

44. INFSO-SSA-26637 44 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Exercise 3: create a Consumer rgma> set query latest Set query type to latest rgma> set maxage 1 minutes Set max age to 1 minutes rgma> set timeout 50 seconds Set timeout to 50 seconds rgma> set output tsv Set output format to 'tsv‘ rgma>select Application,Status FROM TutorTable TestProducer Start TestProducer Step1 TestProducer Step2

45. INFSO-SSA-26637 45 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Exercise 4: Producer & Consumer Continuos Producer and Consumer: (NOTE. Open 2 rgma client tool, one for Consumer the other for Producer.) Consumer’s client: rgma> set query continuous rgma> set timeout 50 seconds rgma> set maxage 30 rgma> set output csv rgma> select * from TutorTable Producer’s client: rgma>clear history rgma> set producer continuous rgma> insert INTO TutorTable values(002,'TestProducer','Step2',20,'Valeria'); rgma> insert INTO TutorTable values(003,'TestProducer','Step3',30,'Valeria'); rgma> insert INTO TutorTable values(004,'TestProducer','Step4',40,'Valeria'); rgma> insert INTO TutorTable values(005,'TestProducer','Step5',50,'Valeria'); rgma> write history Prod_comm.rgma

46. INFSO-SSA-26637 46 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Batch mode The command line tool can be used in batch mode in three ways: rgma –c [ -c …] Executes the command and exit. rgma –f Executes commands in file sequentially and exit. Commands embedded in a shell script: #!/bin/sh $RGMA_HOME/bin/rgma <<EOF set query latest select Application,Status FROM TutorTable EOF

47. INFSO-SSA-26637 47 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Exercise 5: Producer & Consumer Continuos Producer and Consumer: (NOTE. Open 1 rgma client tool only for Consumer. Open one shell for Producer.) Consumer’s client: rgma> set query continuous rgma> set timeout 60 seconds rgma> set output csv rgma> select * from TutorTable Producer’s shell: rgma -c “set producer continuous” rgma -c “insert INTO TutorTable values(006,‘A','Starting',00,'Valeria');” rgma -c “insert INTO TutorTable values(005,‘A',‘Running',30,'Valeria');”

48. INFSO-SSA-26637 48 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 Exercise 6: Producer & Consumer Continuos Producer and Consumer: (NOTE. Open 1 rgma client tool only for Consumer. Open one shell for Producer.) Consumer’s client: rgma> set query continuous rgma> set timeout 60 seconds rgma> write results Results.rgma rgma> select * from ITATutTable Producer’s shell: rgma -f Prod_comm.rgma

49. INFSO-SSA-26637 49 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 R-GMA APIs APIs exist in Java, C, C++. – For clients (servlets contacted behind the scenes) They include methods for… – Creating consumers – Creating primary and secondary producers – Setting type of queries, type of produces, retention periods, time outs… – Retrieving tuples, inserting data – … You can create your own Producer or Consumer.

50. INFSO-SSA-26637 50 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 The R-GMA Browser The easiest way to try out R-GMA. – It is installed on the machine running the Registry and Schema: https://rgmasrv.ct.infn.it:8443/R-GMA Using the Browser you can do the following. – Browse the tables in the schema. – Look at the table definitions. – See all the available producers for a table. – Query a table. – Query only selected producers.

51. INFSO-SSA-26637 51 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 https://rgmasrv.ct.infn.it:8443/R-GMA

52. INFSO-SSA-26637 52 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 R-GMA Web Browser https://rgmasrv.ct.infn.it:8443/R-GMA https://grid.ct.infn.it/twiki/bin/view/GILDA/CertificateMana gement

53. INFSO-SSA-26637 53 Valeria Ardizzone, Grid Computing Course, Univ. of Catania, 22.05.2007 References RGMA exercises on GILDA Wiki: https://grid.ct.infn.it/twiki/bin/view/GILDA/InformationSyste ms#RGMA gLite 3.0 User Guide – https://edms.cern.ch/file/722398/1.1/gLite-3- UserGuide.pdf R-GMA home page – http://www.r-gma.org/ R-GMA in EGEE – http://hepunx.rl.ac.uk/egee/jra1-uk/